Long-term comparison of losartan and enalapril on kidney function in hypertensive type 2 diabetics with early nephropathy

Efficacy of angiotensin receptor blockers for nocturnal blood pressure reduction: a systematic review and meta-analysis

BACKGROUND

Nocturnal blood pressure (BP) is correlated with an increased risk of cardiovascular events and is an important predictor of cardiovascular death in hypertensive patients.

OBJECTIVE

Nocturnal BP control is of great importance for cardiovascular risk reduction. This systematic review and meta-analysis aimed to explore the efficacy of angiotensin receptor blockers (ARBs) for nocturnal BP reduction in patients with mild to moderate hypertension.

METHODS

PICOS design structure was used to formulate the data extraction. All statistical calculations and analyses were performed with R.

RESULTS

Seventy-seven studies with 13,314 participants were included. The overall analysis indicated that nocturnal BP drop varied considerably among different ARBs. Allisartan (13.04 [95% CI (-18.41, -7.68)] mmHg), olmesartan (11.67 [95% CI (-14.12, -9.21)] mmHg), telmisartan (11.11 [95% CI (-12.12, -10.11)] mmHg) were associated with greater reduction in nocturnal systolic BP. In the aspect of the nocturnal-diurnal BP drop ratio, only allisartan was greater than 1. While, the variation tendency of last 4-6 h ambulatory BP was basically consistent with nocturnal BP. Additionally, allisartan showed improvement effect in the proportion of patients with dipping BP pattern.

CONCLUSIONS

This study demonstrates that for patients with mild to moderate hypertension, allisartan, olmesartan and telmisartan have more advantages in nocturnal BP reduction among the ARBs, while allisartan can reduce nighttime BP more than daytime BP and improve the dipping pattern.

Angiotensin-converting-enzyme inhibitors and angiotensin receptor blockers for preventing the progression of diabetic kidney disease

BACKGROUND

Guidelines suggest that adults with diabetes and kidney disease receive treatment with angiotensin-converting-enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). This is an update of a Cochrane review published in 2006.

OBJECTIVES

We compared the efficacy and safety of ACEi and ARB therapy (either as monotherapy or in combination) on cardiovascular and kidney outcomes in adults with diabetes and kidney disease.

SEARCH METHODS

We searched the Cochrane Kidney and Transplants Register of Studies to 17 March 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included studies evaluating ACEi or ARB alone or in combination, compared to each other, placebo or no treatment in people with diabetes and kidney disease.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

One hundred and nine studies (28,341 randomised participants) were eligible for inclusion. Overall, the risk of bias was high. Compared to placebo or no treatment, ACEi may make little or no difference to all-cause death (24 studies, 7413 participants: RR 0.91, 95% CI 0.73 to 1.15; I2 = 23%; low certainty) and with similar withdrawals from treatment (7 studies, 5306 participants: RR 1.03, 95% CI 0.90 to 1.19; I2 = 0%; low certainty). ACEi may prevent kidney failure (8 studies, 6643 participants: RR 0.61, 95% CI 0.39 to 0.94; I2 = 0%; low certainty). Compared to placebo or no treatment, ARB may make little or no difference to all-cause death (11 studies, 4260 participants: RR 0.99, 95% CI 0.85 to 1.16; I2 = 0%; low certainty). ARB have uncertain effects on withdrawal from treatment (3 studies, 721 participants: RR 0.85, 95% CI 0.58 to 1.26; I2 = 2%; low certainty) and cardiovascular death (6 studies, 878 participants: RR 3.36, 95% CI 0.93 to 12.07; low certainty). ARB may prevent kidney failure (3 studies, 3227 participants: RR 0.82, 95% CI 0.72 to 0.94; I2 = 0%; low certainty), doubling of serum creatinine (SCr) (4 studies, 3280 participants: RR 0.84, 95% CI 0.72 to 0.97; I2 = 32%; low certainty), and the progression from microalbuminuria to macroalbuminuria (5 studies, 815 participants: RR 0.44, 95% CI 0.23 to 0.85; I2 = 74%; low certainty). Compared to ACEi, ARB had uncertain effects on all-cause death (15 studies, 1739 participants: RR 1.13, 95% CI 0.68 to 1.88; I2 = 0%; low certainty), withdrawal from treatment (6 studies, 612 participants: RR 0.91, 95% CI 0.65 to 1.28; I2 = 0%; low certainty), cardiovascular death (13 studies, 1606 participants: RR 1.15, 95% CI 0.45 to 2.98; I2 = 0%; low certainty), kidney failure (3 studies, 837 participants: RR 0.56, 95% CI 0.29 to 1.07; I2 = 0%; low certainty), and doubling of SCr (2 studies, 767 participants: RR 0.88, 95% CI 0.52 to 1.48; I2 = 0%; low certainty). Compared to ACEi plus ARB, ACEi alone has uncertain effects on all-cause death (6 studies, 1166 participants: RR 1.08, 95% CI 0.49 to 2.40; I2 = 20%; low certainty), withdrawal from treatment (2 studies, 172 participants: RR 0.78, 95% CI 0.33 to 1.86; I2 = 0%; low certainty), cardiovascular death (4 studies, 994 participants: RR 3.02, 95% CI 0.61 to 14.85; low certainty), kidney failure (3 studies, 880 participants: RR 1.36, 95% CI 0.79 to 2.32; I2 = 0%; low certainty), and doubling of SCr (2 studies, 813 participants: RR 1.14, 95% CI 0.70 to 1.85; I2 = 0%; low certainty). Compared to ACEi plus ARB, ARB alone has uncertain effects on all-cause death (7 studies, 2607 participants: RR 1.02, 95% CI 0.76 to 1.37; I2 = 0%; low certainty), withdrawn from treatment (3 studies, 1615 participants: RR 0.81, 95% CI 0.53 to 1.24; I2 = 0%; low certainty), cardiovascular death (4 studies, 992 participants: RR 3.03, 95% CI 0.62 to 14.93; low certainty), kidney failure (4 studies, 2321 participants: RR 1.15, 95% CI 0.67 to 1.95; I2 = 29%; low certainty), and doubling of SCr (3 studies, 2252 participants: RR 1.18, 95% CI 0.85 to 1.64; I2 = 0%; low certainty). Comparative effects of different ACEi or ARB and low-dose versus high-dose ARB were rarely evaluated. No study compared different doses of ACEi. Adverse events of ACEi and ARB were rarely reported.

AUTHORS' CONCLUSIONS

ACEi or ARB may make little or no difference to all-cause and cardiovascular death compared to placebo or no treatment in people with diabetes and kidney disease but may prevent kidney failure. ARB may prevent the doubling of SCr and the progression from microalbuminuria to macroalbuminuria compared with a placebo or no treatment. Despite the international guidelines suggesting not combining ACEi and ARB treatment, the effects of ACEi or ARB monotherapy compared to dual therapy have not been adequately assessed. The limited data availability and the low quality of the included studies prevented the assessment of the benefits and harms of ACEi or ARB in people with diabetes and kidney disease. Low and very low certainty evidence indicates that it is possible that further studies might provide different results.

A Comparative Study of the Safety and Efficacy Between Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers on the Management of Hypertension: A Systematic Review

Renin-angiotensin-aldosterone system (RAAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are commonly used in the management of hypertension. High blood pressure is a vital risk factor for cardiovascular disease. This study aims to establish any significant difference in using ACEIs and ARBs in managing hypertension. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct this systematic review. We searched PubMed, MEDLINE, and ScienceDirect for articles published in the last 20 years (2003 to 2023). Our search was last done on the 27th of June, 2023. Following the initial search, 8,313 articles were found on PubMed. After screening the articles selected from the databases, 10 articles examining 1,621,445 patients were selected for the final study. Three articles were identified that compared ACEI and ARB in their capacity to lower blood pressure. Six articles compared both medications' capacity to reduce cardiovascular events and mortality. Five articles were identified that compared both classes of drugs for adverse effects. This study was made to determine whether or not there is a difference between the use of ACEIs and ARBs in the treatment of hypertension. The study showed that both ACEIs and ARBs are similar in their efficacy in lowering blood pressure. However, ACEI was revealed to be superior to ARB in reducing cardiovascular events and all-cause mortality. ARB was shown to be better tolerated by patients than ACEI.

Acute and chronic kidney complications in children with type 1 diabetes mellitus

Children with type 1 diabetes mellitus (T1DM) have an increased risk of developing kidney involvement. Part of the risk establishes at the beginning of T1DM. In fact, up to 65% of children during T1DM onset may experience an acute kidney injury (AKI) which predisposes to the development of a later chronic kidney disease (CKD). The other part of the risk establishes during the following course of T1DM and could be related to a poor glycemic control and the subsequent development of diabetic kidney disease. In this review, we discuss the acute and chronic effects of T1DM on the kidneys, and the implications of these events on the long-term prognosis of kidney function.

Effectiveness of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers on total and cardiovascular mortality and morbidity in primary prevention: A nationwide study based on French Health Insurance Data (SNDS)

Angiotensin‐converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) both inhibit the renin‐angiotensin system (RAS) but have different sites of action. Whether clinically meaningful differences exist is still debated. The authors set up a population‐based nationwide retrospective cohort study with at least 5 years of follow‐up based on the comprehensive French Health Insurance Database linked to the French hospital discharge database. Patients aged 50 or above, identified as ARB or ACE inhibitor new users in 2009 (at least one delivery during the year and no such delivery in 2008) were eligible. Exclusion criteria included history of cancer, cardiovascular disease, or chronic renal insufficiency. Main outcome measure was overall mortality. Secondary outcomes were cardiovascular deaths, major cardiovascular events, and major or other cardiovascular events. Out of 407 815 eligible patients, 233 682 (57%) were ARB users; two‐third had no previous exposure to antihypertensive drug. Based on propensity‐score based Cox model, ARB new user group had a better overall (HR: .878, 95%CI, .854 to .902), and cardiovascular (HR: .841, 95%CI, .800 to .84) survival and had a lower risk for major cardiovascular events (HR: .886, 95%CI, .868 to .905). Statistically significant quantitative interactions were detected with diabetes. Considering subgroup analyses, ARBs had a better survival than ACE inhibitors in nondiabetic patients.

Esaxerenone (CS-3150) in Patients with Type 2 Diabetes and Microalbuminuria (ESAX-DN): Phase 3 Randomized Controlled Clinical Trial

BACKGROUND AND OBJECTIVES

Diabetic kidney disease is an important complication of type 2 diabetes. In a phase 2b study, adding esaxerenone to renin-angiotensin system inhibitors dose dependently reduced the urinary albumin-to-creatinine ratio in patients with type 2 diabetes and microalbuminuria. This 52-week phase 3 study further investigated the effects of esaxerenone on the urinary albumin-to-creatinine ratio in this patient group.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this multicenter, randomized, double-blind study, patients with type 2 diabetes and a urinary albumin-to-creatinine ratio of 45 to <300 mg/g creatinine treated with renin-angiotensin system inhibitors were randomized to esaxerenone or placebo for 52 weeks (n=455). Esaxerenone was initiated at 1.25 mg/d and titrated to 2.5 mg/d on the basis of serum potassium monitoring. The primary endpoint was the proportion of patients achieving urinary albumin-to-creatinine ratio remission (<30 mg/g creatinine and ≥30% reduction from baseline on two consecutive occasions).

RESULTS

Overall, 49 (22%) and nine (4%) patients in the esaxerenone and placebo groups, respectively, achieved urinary albumin-to-creatinine ratio remission (absolute difference 18%; 95% confidence interval, 12% to 25%; P<0.001). The percent change in urinary albumin-to-creatinine ratio from baseline to end of treatment was significantly higher with esaxerenone versus placebo (-58% versus 8%; geometric least-squares mean ratio to placebo 0.38, 95% confidence interval, 0.33 to 0.44). There was a significant improvement with esaxerenone versus placebo in time to first remission (hazard ratio, 5.13; 95% confidence interval, 3.27 to 8.04) and time to first transition to urinary albumin-to-creatinine ratio ≥300 mg/g creatinine (hazard ratio, 0.23; 95% confidence interval, 0.11 to 0.48). More patients had a serum potassium level ≥6.0 or ≥5.5 mEq/L on two consecutive measurements in the esaxerenone group (20 [9%]) versus placebo (5 [2%]); these events were asymptomatic and resolved after dosage reduction or treatment discontinuation.

CONCLUSIONS

Adding esaxerenone to existing renin-angiotensin system inhibitor therapy in patients with type 2 diabetes and microalbuminuria increased the likelihood of albuminuria returning to normal levels, and reduced progression of albuminuria to higher levels.

The Use of Renin-Angiotensin System Inhibitors in Patients With Chronic Kidney Disease

Chronic kidney disease (CKD) is a growing public health issue worldwide. It is acknowledged that CKD is associated with increased risk of cardiovascular disease, which is the leading cause of morbidity and mortality in this population. The role of the renin-angiotensin-aldosterone system in the pathophysiology of hypertension, and cardiovascular and kidney diseases is well known and the renin-angiotensin-aldosterone system is a major regulator of blood pressure through its effect on body fluids and electrolyte homeostasis. For 2 decades, renin-angiotensin system inhibitors have been the mainstay of treatment for CKD. Clinical trials have shown that prescription of monotherapy with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers reduces albuminuria and slows the progression of nephropathy in patients with diabetes. In clinical practice guidelines, renin-angiotensin system inhibitors are recommended as the antihypertensive drug of choice in patients with CKD with or without diabetes. Moreover, renin-angiotensin system inhibitors have been shown to offer cardiovascular protection beyond those resulting after blood pressure control. However, the benefits of renin-angiotensin system inhibitor prescriptions for patients with advanced CKD remain controversial. Patients with advanced CKD or who undergo dialysis are under-represented in clinical trials, and studies in this population are urgently needed.

Pharmacological Management of Diabetic Nephropathy

INTRODUCTION

Diabetes mellitus (DM) is one of the most common diseases worldwide. Its adverse effects on several body organs, have made treatment of DM a priority. One of the most serious complications of DM is diabetic nephropathy (DN).

OBJECTIVE

The aim of this review is to critically discuss available data on the pharmacological management of DN.

METHODS

A comprehensive review of the literature was performed to identify studies assessing the impact of several drug classes on DN.

RESULTS

Several studies have been conducted in order to find a novel and effective treatment of DN. So far, the cornerstone therapy of DN consists of renin-angiotensin system (RAS) inhibitors, agents that decrease the synthesis of intrarenal angiotensin II or block its receptors. Their antiproteinuric and antihypertensive effects can not only decelerate the progress of DN but prevent its onset as well. Novel antidiabetic drugs, such as sodium-glucose cotransporter 2 inhibitors (SGLT-2i) and glucagon-like peptide- 1 receptor agonists (GLP-1 RA), are promising agents in the therapy of DN, due to their positive effect on renal and cardiovascular adverse events. From lipid-lowering agents, atorvastatin improves DN up to stage 3 and substantially reduces CVD.

CONCLUSION

RAS inhibitors, SGLT-2i and GLP-1 agonists were found to be beneficial for the treatment of DN. Larger renal trials are needed in order to incorporate these drugs into the first line treatment of DN.

The Long-Term Impact of Renin-Angiotensin System (RAS) Inhibition on Cardiorenal Outcomes (LIRICO): A Randomized, Controlled Trial

BACKGROUND

The comparative effectiveness of treatment with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or their combination in people with albuminuria and cardiovascular risk factors is unclear.

METHODS

In a multicenter, randomized, open label, blinded end point trial, we evaluated the effectiveness on cardiovascular events of ACE or ARB monotherapy or combination therapy, targeting BP<130/80 in patients with moderate or severe albuminuria and diabetes or other cardiovascular risk factors. End points included a primary composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for cardiovascular causes and a revised end point of all-cause mortality. Additional end points included ESRD, doubling of serum creatinine, albuminuria, eGFR, BP, and adverse events.

RESULTS

Because of slow enrollment, the trial was modified and stopped 41% short of targeted enrollment of 2100 participants, corresponding to 35% power to detect a 25% reduced risk in the primary outcome. Our analysis included 1243 adults, with median follow-up of 2.7 years. Efficacy outcomes were similar between groups (ACE inhibitor versus ARB, ACE inhibitor versus combination, ARB versus combination) as were rates of serious adverse events. The rate of permanent discontinuation for ARB monotherapy (6.3%) was significantly lower than for ACE inhibitor monotherapy (15.7%) or combined therapy (18.3%).

CONCLUSIONS

Patients may tolerate ARB monotherapy better than ACE inhibitor monotherapy. However, data from this trial and similar trials, although as yet inconclusive, show no trend suggesting differences in mortality and renal outcomes with ACE inhibitors or ARBs as dual or monotherapy in patients with albuminuria and diabetes or other cardiovascular risk factors.

Long-Term Administration of Angiotensin (1-7) to db/db Mice Reduces Oxidative Stress Damage in the Kidneys and Prevents Renal Dysfunction

Aims

The goal of this study was to evaluate the effects of long-term (16 weeks) administration of angiotensin (1–7) [A(1–7)] on kidney function in db/db mice and to identify the protective mechanisms of this therapy.

Methods

db/db mice and heterozygous controls were treated with A(1–7) or vehicle daily, subcutaneously for up to 16 weeks. Kidney injury was assessed by measuring blood flow in renal arteries, plasma creatinine levels, and proteinuria. Effects of treatment on oxidative stress were evaluated by histological staining and gene expression.

Results

16 weeks of daily administration of A(1–7) to a mouse model of severe type 2 diabetes (db/db) prevented the progression of kidney damage. Treatment with A(1–7) improved blood flow in the renal arteries, as well as decreased plasma creatinine levels and proteinuria in diabetic mice. Reduction of oxidative stress was identified as one of the mechanisms of the renoprotective action of A(1–7). Treatment prevented formation of nitrotyrosine residues, a marker of oxidative stress damage. A(1–7) also reduced the expression of two enzymes involved in formation of nitrotyrosine, namely, eNOS and NOX-4. A(1–7) regulated the phosphorylation pattern of eNOS to enhance production of NO in diabetic animals, possibly through the Akt pathway. However, these elevated levels of NO did not result in increased nitrosylation, possibly due to reduced NOX-4 levels.

Conclusions

Long-term administration of A(1–7) improved kidney function and reduced oxidative stress damage in db/db mice.

The protective role of melatonin in chemotherapy-induced nephrotoxicity: a systematic review of non-clinical studies

BSTRACT Introduction: The aim of this study was to investigate the potential role of melatonin in the prevention of chemotherapy-induced nephrotoxicity at the preclinical level. Areas to be covered: To illuminate the possible role of melatonin in preventing chemotherapy-related nephrotoxicity, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed. A comprehensive search strategy was developed to include PubMed, Web of Science, Scopus, and Embase electronic databases from their inception to May 2018. Based on a set of prespecified inclusion and exclusion criteria, 21 non-clinical articles were ultimately included in the study. Expert opinion: Our findings clearly demonstrate that melatonin has a protective role in the prevention of chemotherapy-induced nephrotoxicity which may be caused by different chemotherapy agents such as cyclophosphamide, cisplatin, doxorubicin, methotrexate, oxaliplatin, etoposide, and daunorubicin. On the basis of current review of non-clinical studies, this protective effect of melatonin is attributed to different mechanisms such as reduction of oxidative stress, apoptosis, and inflammation. The findings presented in this review are based on non-clinical studies and thus conducting appropriate clinical trials to evaluate the real effectiveness of the concurrent use of chemotherapy agents with melatonin in the cancer patients is necessary.

Angiotensin-Converting Enzyme Inhibitors vs. Angiotensin Receptor Blockers for the Treatment of Hypertension in Adults With Type 2 Diabetes: Why We Favour Angiotensin Receptor Blockers

Cardiovascular disease is the principal cause of morbidity and mortality in patients with diabetes mellitus. The incidence or progression of kidney disease is also common in these patients. Several clinical trials have established the efficacy of angiotensin receptor blockers for the prevention of adverse cardiovascular and renal outcomes in this population and are summarized in this review article. Head-to-head comparison of angiotensin receptor blockers with angiotensin-converting enzyme inhibitors has shown similar cardioprotective and renoprotective properties of both medication classes. However, angiotensin receptor blockers have an improved safety profile with fewer episodes of cough and angioedema and may be the agent of choice in patients with diabetes and hypertension. Novel therapeutic strategies, such as those that include a mineralocorticoid receptor blocker or a selective sodium-glucose cotransporter type 2 inhibitor, may further protect patients with diabetes from cardiovascular and renal complications.

Update of pathophysiology and management of diabetic kidney disease

Diabetic kidney disease (DKD) is a major cause of morbidity and mortality in patients with diabetes mellitus and the leading cause of end-stage renal disease in the world. The most characteristic marker of DKD is albuminuria, which is associated with renal disease progression and cardiovascular events. Renal hemodynamics changes, oxidative stress, inflammation, hypoxia and overactive renin-angiotensin-aldosterone system (RAAS) are involved in the pathogenesis of DKD, and renal fibrosis plays the key role. Intensified multifactorial interventions, including RAAS blockades, blood pressure and glucose control, and quitting smoking, help to prevent DKD development and progression. In recent years, novel agents are applied for preventing DKD development and progression, including new types of glucose-lowering agents, pentoxifylline, vitamin D analog paricalcitol, pyridoxamine, ruboxistaurin, soludexide, Janus kinase inhibitors and nonsteroidal minerocorticoid receptor antagonists. In this review, recent large studies about DKD are also summarized.

Cost-effectiveness of angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers as first-line treatment in autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a rare kidney disorder impacting ∼1:2,500 individuals among the general US population. Hypertension is a significant predictor of ADPKD progression, and a risk factor for development of cardiovascular disease (CVD), the most common cause for mortality among ADPKD patients. Angiotensin-converting enzymes inhibitors (ACE-I) are widely used as first-line treatment in ADPKD for the management of hypertension. However, their cost-effectiveness relative to other hypertensive medications, such as angiotensin II receptor blockers (ARB), has never been assessed.

OBJECTIVE

To determine if ARB are more cost-effective than ACE-Is as first-line treatment in ADPKD.

METHODS

A Markov-state decision model was constructed for estimation of cost and outcome benefits in hypertensive ADPKD patients. Transition probabilities were extrapolated from a retrospective cohort study comparing chronic kidney disease (CKD) stage transitions in ADPKD patients. Annual pharmaceutical costs per average daily dose per CKD stage were extracted from a US healthcare claims database. Median total healthcare costs per CKD stage or transplant were extracted from the published literature. The time horizon was set to 30 years, with 1-year duration to cycle shift. A cost-effectiveness analysis was conducted to estimate the incremental cost-effectiveness ratio (ICER) of ACE-I vs ARB per additional year of prevented transplant and/or death. A one-way probabilistic sensitivity analysis was conducted, with 10% variation in probabilities and cost.

RESULTS

Total annual healthcare costs accrued after 30 years among ADPKD patients taking ACE-Is was estimated to be $3,505,028.41, compared to ARB at $3,644,327.65. Life expectancy was increased by 1.39 years among patients taking ACE-I. Approximate 10-year survival in patients taking ACE-Is was 47% compared to ARB at 34%.

CONCLUSIONS

ACE-I dominated ARB and displayed greater cost-effectiveness due to lower cost and increased capacity to prolong years of life without transplant or death among hypertensive ADPKD patients. This model strengthens the value of ACE-I over ARB as first-line treatment for hypertension management in ADPKD patients.

Comparative Efficacy and Safety of Antihypertensive Agents for Adult Diabetic Patients with Microalbuminuric Kidney Disease: A Network Meta-Analysis

BACKGROUND

Antihypertensive treatment mitigates the progression of chronic kidney disease. Here, we comparatively assessed the effects of antihypertensive agents in normotensive and hypertensive diabetic patients with microalbuminuric kidney disease.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched for randomized controlled trials (RCTs) comparing oral antihypertensive agents in adult diabetic patients with microalbuminuria. The primary efficacy outcome was reduction in albuminuria, and the primary safety outcomes were dry cough, presyncope, and edema. Random-effects pairwise and Bayesian network meta-analyses were performed to produce outcome estimates for all RCTs, only hypertensive RCTs, or only normotensive RCTs. Surface under the cumulative ranking (SUCRA) probability rankings were calculated for all outcomes. Sensitivity analyses on type 2 diabetes status, age, or follow-up duration were also performed.

RESULTS

A total of 38 RCTs were included in the meta-analyses. The angiotensin-converting enzyme inhibitor-calcium channel blocker (ACEI-CCB) combination therapy of captopril+diltiazem was most efficacious in reducing albuminuria irrespective of blood pressure status. However, the ACEI-angiotensin receptor blocker (ACEI-ARB) combination therapy of trandolapril+candesartan was the most efficacious in reducing albuminuria for normotensive patients, while the ACEI-CCB combination therapy of fosinopril+amlodipine was the most efficacious in reducing albuminuria for hypertensive patients. The foregoing combination therapies displayed inferior safety profiles relative to ACEI monotherapy with respect to dry cough, presyncope, and edema. With respect to type 2 diabetic patients with microalbuminuria, the Chinese herbal medicine Tangshen formula followed by the ACEI ramipril were the most efficacious in reducing albuminuria.

CONCLUSIONS

Trandolapril+candesartan appears to be the most efficacious intervention for reducing albuminuria for normotensive patients, while fosinopril+amlodipine appears to be the most efficacious intervention for reducing albuminuria for hypertensive patients. For practitioners opting for monotherapy, our SUCRA analysis supports the use of trandolapril and fosinopril in normotensive and hypertensive adult diabetic patients with microalbuminuria, respectively.

Treating Gout in Kidney Transplant Recipients

Objective

To review the etiology, treatment, and preventive strategies of hyperuricemia and gout in kidney transplant recipients.

Data Sources

Primary literature was obtained via Medline (1966-June 2003).

Study Selection and Data Extraction

Studies evaluating treatment and prevention of hyperuricemia and gout in kidney transplantation were considered for evaluation. English-language studies were selected for inclusion.

Data Synthesis

Approximately 14000 kidney transplantations were performed in the United States in 2003, and of those transplant recipients, nearly 13% will experience a new onset of gout. The prevalence of hyperuricemia is even greater. There are several mechanisms by which hyperuricemia and gout develop in kidney transplant recipients. Medication-induced hyperuricemia and renal dysfunction are 2 of the more common mechanisms. Prophylactic and treatment options include allopurinol, colchi cine, corticosteroids, and, if absolutely necessary, nonsteroidal anti-inflammatory drugs.

Conclusion

It is generally recommended to decide whether the risks of prophylactic therapy and treatment outweigh the benefits. Often, the risk of adverse events associated with agents to treat these ailments tends to outweigh the benefits; therefore, treatment is usually reserved for symptomatic episodes of acute gout. Practitioners must also decide if changes in immunosuppressive regimens may be of benefit on a patient-by-patient basis.

Effects of ACE Inhibition and Angiotensin II Receptor Blockade on Glomerular Basement Membrane Protein Excretion and Charge Selectivity in Type 2 Diabetic Patients

Angiotensin-converting enzyme (ACE) inhibitors may reduce urinary albumin excretion (UAE) by decreasing glomerular pressure and increasing glomerular charge selectivity through preservation of glycosaminoglycans. The effect of Angiotensin II antagonism on glomerular charge selectivity remains to be determined. The aim of this study was to compare the effects of an AT1 blocker losartan and an ACE inhibitor (ACE-I) enalapril on UAE, extracellular matrix proteins, glycosaminoglycan excretion (UGAG) and red blood cell anionic charge (RBCCh) which are the indirect markers of glomerular basement membrane anionic content in hypertensive Type 2 diabetic patients. Twenty-four patients were randomised into two groups and received either enalapril (5—20 mg/d) or losartan (50—100 mg/d). All parameters were measured at baseline and after six months of treatment. At the end of six months, systolic and diastolic blood pressures (BP), UAE rates, UGAG excretion and RBCCh were significantly and equally reduced in both treatment groups compared with baseline. RBCCh was negatively correlated with UAE (r=-0. O 57, p<0.0001) and UGAG excretion (r=-0.57, Rp<0.0001); UAE was correlated with UGAG excretion (r=0.58, p<0.0001). In conclusion, enalapril and losartan treatment were equally effective in reducing BP, UAE as well as UGAG excretion and preserving RBCCh in hypertensive Type 2 diabetic patients. ACE inhibition and AT1-receptor blockade may have favourable effects on preserving glomerular anionic content in hypertensive diabetic patients.

Relationship Between Medication Adherence and Distance to Dispensing Pharmacies and Prescribers Among an Urban Medicaid Population with Diabetes Mellitus

STUDY OBJECTIVE

To determine whether a relationship exists between medication adherence to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) and distance to dispensing pharmacies and prescribers among an urban public aid population with diabetes mellitus.

DESIGN

Retrospective cohort study using claims data.

DATA SOURCE

Illinois Department of Healthcare and Family Services database.

PATIENTS

A total of 6532 patients aged 18-64 years with diabetes who had at least one prescription fill for an ACEI or ARB and had continuous Medicaid coverage in the greater Chicago area in 2009.

MEASUREMENTS AND MAIN RESULTS

We assessed medication adherence, defined as proportion of days covered (PDC) of 0.8 or higher, to ACEIs and ARBs and its association with distances between patients and their pharmacies and prescribers. Of the 6532 patients included in the analyses, 2930 (45%) had PDC levels of 0.8 or higher. No significant differences were observed between patients who were adherent versus those who were nonadherent in distance to pharmacy (median 1.39 vs 1.35 miles, p=0.15) or distance to prescriber (median 4.39 vs 4.48 miles, p=0.80). In a multivariate regression model including age, sex, race/ethnicity, number of pharmacies, number of prescribers, distance to pharmacy, and distance to prescriber, a greater number of prescribers was associated with higher adherence (two prescribers vs one prescriber: odds ratio [OR] 1.396, 95% confidence interval [CI] 1.233-1.580; three or more prescribers vs one prescriber: OR 2.208, 95% CI 1.787-2.727).

CONCLUSION

ACEI or ARB adherence was not associated with distances to pharmacies and prescribers.

Comparing the effect of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers on renal function decline in diabetes

AIM

To compare effectiveness of angiotensin-converting enzyme inhibitors (ACEis)/angiotensin receptor blockers (ARBs) for protecting Type 2 diabetes mellitus (DM2) patients from renal function decline in a real-world setting.

METHODS

Retrospective cohort study of new ACEi/ARB users in 2007-2012 in an unselected primary care DM2 population. Outcome is decline in renal function stage (combining estimated glomerular filtration rate and albuminuria). Patients were matched on a propensity score. Extended Cox models with time-varying covariates were used to estimate hazard ratios of outcome.

RESULTS

The time to renal function decline for ARB users was slightly, but not significantly longer than for ACEi users (hazard ratio: 0.80; 95% CI: 0.58-1.10; p = 0.166).

CONCLUSION

This study did not show significant differences between the classes in preventing renal function decline in DM2 patients in primary care.

A comparison between angiotensin converting enzyme inhibitors and angiotensin receptor blockers on end stage renal disease and major adverse cardiovascular events in diabetic patients: a population-based dynamic cohort study in Taiwan

Background

Contemporary guidelines recommend angiotensin-converting-enzyme inhibitors (ACEi) or angiotensin-receptor blockers (ARB) for hypertensive patients with diabetes. However, there is limited data to evaluate the comparison between ACEi and ARB on end stage renal disease (ESRD) and major adverse cardiovascular events (MACE), in Asian diabetic patients.

Methods

We used the Taiwan Longitudinal Cohort of Diabetes Patients Database to perform a population-based dynamic cohort study. The comparison between ACEi and ARB on ESRD and MACE in diabetic patients was examined using the propensity score weighting method. We followed these patients until the occurrence of first study outcomes or end date of the study, whichever came first.

Results

There were 6898 and 12,758 patients in ACEi and ARB groups, respectively. The mean follow-up period was about 3.5 years in ESRD and 2.5 years in MACE. The incidence of ESRD was 0.44 % and 0.63 % per person-years in the ACEi and ARB group, respectively. The risk of ESRD was lower in the ACEi group than the ARB group [hazard ratio (HR) 0.69; 95 % confidence interval (CI) 0.54–0.88, P = 0.0025]. Among those without chronic kidney disease (CKD), the incidence of ESRD was 0.30 % and 0.37 % per person-years in the ACEi and ARB group, respectively. ACEi was similar to ARB in preventing ESRD for those without CKD (P = 0.11). Among those with CKD, the incidence of ESRD was 1.39 % and 2.34 % per person-years in the ACEi and ARB group, respectively. The ACEi group had a lower risk of ESRD than the ARB group (HR 0.61; 95 % CI 0.42–0.88, P = 0.008). The incidence of MACE was 9.33 % and 9.62 % per person-years in the ACEi and ARB group, respectively. There was no significant difference in the composite MACE outcome between the two groups (P = 0.42), but the ACEi group was associated with a higher risk of stroke than the ARB group (HR 1.12; 95 % CI 1.02–1.24, P = 0.02).

Conclusions

ACEi compared with ARB was associated with a lower incidence of ESRD, especially in those with CKD. Though ACEi and ARB had a similar risk of composite MACE outcome, ACEi had a slightly higher incidence of stroke than ARB, among the Asian diabetic patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0365-x) contains supplementary material, which is available to authorized users.

Comparative effectiveness of angiotensin-converting-enzyme inhibitors and angiotensin II receptor blockers in patients with type 2 diabetes and retinopathy

BACKGROUND

Angiotensin-converting-enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are effective treatments for diabetic retinopathy, but randomized trials and meta-analyses comparing their effects on macrovascular complications have yielded conflicting results. We compared the effectiveness of these drugs in patients with pre-existing diabetic retinopathy in a large population-based cohort.

METHODS

We conducted a propensity score-matched cohort study using Taiwan's National Health Insurance Research Database. We included adult patients prescribed an ACE inhibitor or ARB within 90 days after diagnosis of diabetic retinopathy between 2000 and 2010. Primary outcomes were all-cause death and major adverse cardiovascular events (myocardial infarction, ischemic stroke or cardiovascular death). Secondary outcomes were hospital admissions with acute kidney injury or hyperkalemia.

RESULTS

We identified 11 246 patients receiving ACE inhibitors and 15 173 receiving ARBs, of whom 9769 patients in each group were matched successfully by propensity scores. In the intention-to-treat analyses, ARBs were similar to ACE inhibitors in risk of all-cause death (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.87-1.01) and major adverse cardiovascular events (HR 0.95, 95% CI 0.87-1.04), including myocardial infarction (HR 1.03, 95% CI 0.88-1.20), ischemic stroke (HR 0.94, 95% CI 0.85-1.04) and cardiovascular death (HR 1.01, 95% CI 0.88-1.16). They also did not differ from ACE inhibitors in risk of hospital admission with acute kidney injury (HR 1.01, 95% CI 0.91-1.13) and hospital admission with hyperkalemia (HR 1.01, 95% CI 0.86-1.18). Results were similar in as-treated analyses.

INTERPRETATION

Our study showed that ACE inhibitors were similar to ARBs in risk of all-cause death, major adverse cardiovascular events and adverse effects among patients with pre-existing diabetic retinopathy.

Fixed-Dose Combinations of Renin-Angiotensin System Inhibitors and Calcium Channel Blockers in the Treatment of Hypertension: A Comparison of Angiotensin Receptor Blockers and Angiotensin-Converting Enzyme Inhibitors

Fixed-dose combinations (FDCs) of different regimens are recommended in guidelines for the treatment of hypertension. However, clinical studies comparing FDCs of angiotensin receptor blocker (ARB)/calcium channel blocker (CCB) and angiotensin-converting enzyme inhibitor (ACE inhibitor)/CCB in hypertensive patients are lacking.Using a propensity score matching of 4:1 ratio, this retrospective claims database study compared 2 FDC regimens, ARB/CCB and ACE inhibitor/CCB, in treating hypertensive patients with no known atherosclerotic cardiovascular disease. All patients were followed for at least 3 years or until the development of major adverse cardiovascular events (MACEs) during the study period. In addition, the effect of medication adherence on clinical outcomes was evaluated in subgroup analysis based on different portions of days covered.There was no significant difference in MACE-free survival (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 0.98-1.50; P = 0.08) and survival free from hospitalization for heart failure (HR: 1.15; 95% CI: 082-1.61; P = 0.431), new diagnosis of chronic kidney disease (HR: 0.98; 95% CI: 071-1.36; P = 0.906), and initiation of dialysis (HR: 0.99; 95% CI: 050-1.92; P = 0.965) between the 2 study groups. The results remained the same within each subgroup of patients with different adherence statuses.ARBs in FDC regimens with CCBs in the present study were shown to be as effective as ACE inhibitors at reducing the risks of MACEs, hospitalization for heart failure, new diagnosis of chronic kidney disease, and new initiation of dialysis in hypertensive patients, regardless of the medication adherence status.

Renin-Angiotensin System Inhibitors and Kidney and Cardiovascular Outcomes in Patients With CKD: A Bayesian Network Meta-analysis of Randomized Clinical Trials

BACKGROUND

There is much uncertainty regarding the relative effects of angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) in populations with chronic kidney disease (CKD).

STUDY DESIGN

Systematic review and Bayesian network meta-analysis.

SETTING & POPULATION

Patients with CKD treated with renin-angiotensin system (RAS) inhibitors.

SELECTION CRITERIA FOR STUDIES

Randomized trials in patients with CKD treated with RAS inhibitors.

PREDICTOR

ACE inhibitors and ARBs compared to each other and to placebo and active controls.

OUTCOME

Primary outcome was kidney failure; secondary outcomes were major cardiovascular events, all-cause death.

RESULTS

119 randomized controlled trials (n = 64,768) were included. ACE inhibitors and ARBs reduced the odds of kidney failure by 39% and 30% (ORs of 0.61 [95% credible interval, 0.47-0.79] and 0.70 [95% credible interval, 0.52-0.89]), respectively, compared to placebo, and by 35% and 25% (ORs of 0.65 [95% credible interval, 0.51-0.80] and 0.75 [95% credible interval, 0.54-0.97]), respectively, compared with other active controls, whereas other active controls did not show evidence of a significant effect on kidney failure. Both ACE inhibitors and ARBs produced odds reductions for major cardiovascular events (ORs of 0.82 [95% credible interval, 0.71-0.92] and 0.76 [95% credible interval, 0.62-0.89], respectively) versus placebo. Comparisons did not show significant effects on risk for cardiovascular death. ACE inhibitors but not ARBs significantly reduced the odds of all-cause death versus active controls (OR, 0.72; 95% credible interval, 0.53-0.92). Compared with ARBs, ACE inhibitors were consistently associated with higher probabilities of reducing kidney failure, cardiovascular death, or all-cause death.

LIMITATIONS

Trials with RAS inhibitor therapy were included; trials with direct comparisons of other active controls with placebo were not included.

CONCLUSIONS

Use of ACE inhibitors or ARBs in people with CKD reduces the risk for kidney failure and cardiovascular events. ACE inhibitors also reduced the risk for all-cause mortality and were possibly superior to ARBs for kidney failure, cardiovascular death, and all-cause mortality in patients with CKD, suggesting that they could be the first choice for treatment in this population.

Renin-Angiotensin-Aldosterone System Blockade in Diabetic Nephropathy. Present Evidences

Diabetic Kidney Disease (DKD) is the leading cause of chronic kidney disease in developed countries and its prevalence has increased dramatically in the past few decades. These patients are at an increased risk for premature death, cardiovascular disease, and other severe illnesses that result in frequent hospitalizations and increased health-care utilization. Although much progress has been made in slowing the progression of diabetic nephropathy, renal dysfunction and the development of end-stage renal disease remain major concerns in diabetes. Dysregulation of the renin-angiotensin-aldosterone system (RAAS) results in progressive renal damage. RAAS blockade is the cornerstone of treatment of DKD, with proven efficacy in many arenas. The theoretically-attractive option of combining these medications that target different points in the pathway, potentially offering a more complete RAAS blockade, has also been tested in clinical trials, but long-term outcomes were disappointing. This review examines the “state of play” for RAAS blockade in DKD, dual blockade of various combinations, and a perspective on its benefits and potential risks.

Effects of ACEIs Versus ARBs on Proteinuria or Albuminuria in Primary Hypertension: A Meta-Analysis of Randomized Trials

Although angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) belong to a family of therapies that block the renin-angiotensin system and are suggested to improve proteinuria/albuminuria, it is unclear which is more effective. To compare the effects of ACEIs and ARBs on proteinuria in primary hypertension by performing a meta-analysis covering randomized controlled trials (RCTs). We systematically searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1990 to November 2014. Eligible studies were RCTs of ACEI therapy versus ARB therapy that reported the albumin excretion rate (AER), albumin (Alb), and urinary albumin excretion (UAE) as outcomes. Seventeen RCTs, including 17,951 patients (without limit of race, age, or sex) with a mean duration of 62.6 weeks, were included. Pooled analysis suggested that ACEIs and ARBs showed no significant differences in AER/Alb/UAE/24-h urine protein/24-h urine total protein in a comparison of 10 trials (SMD 0.09; 95% CI -0.18-0.36; P = 0.52). No significant differences were observed in urinary protein/creatinine ratio (UPCR)/urinary albumin/creatinine ratio (UACR), or albumin/creatinine ratio (ACR) in 7 trials (SMD 0.15; 95% CI -1.88-2.19; P = 0.88). The total outcome of ACEIs and ARBs also showed no significant difference (SMD 0.13; 95% CI -1.03-1.29; P = 0.83). The efficacies of ACEIs and ARBs in controlling blood pressure as a secondary indicator were also similar (SMD -0.50; 95% CI -1.58-0.58; P = 0.37). Based on a meta-analysis of 17 randomized controlled trials including 17,951 patients, we found that ACEIs and ARBs can reduce urine protein levels, improve blood pressure, and were similarly effective in terms of reducing urinary protein excretion.

Angiotensin converting enzyme (ACE) inhibitors versus angiotensin receptor blockers for primary hypertension

BACKGROUND

Angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs) are widely prescribed for primary hypertension (systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg). However, while ACE inhibitors have been shown to reduce mortality and morbidity in placebo-controlled trials, ARBs have not. Therefore, a comparison of the efficacies of these two drug classes in primary hypertension for preventing total mortality and cardiovascular events is important.

OBJECTIVES

To compare the effects of ACE inhibitors and ARBs on total mortality and cardiovascular events, and their rates of withdrawals due to adverse effects (WDAEs), in people with primary hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the World Health Organization (WHO) International Clinical Trials Registry Platform, and the ISI Web of Science up to July 2014. We contacted study authors for missing and unpublished information, and also searched the reference lists of relevant reviews for eligible studies.

SELECTION CRITERIA

We included randomized controlled trials enrolling people with uncontrolled or controlled primary hypertension with or without other risk factors. Included trials must have compared an ACE inhibitor and an ARB in a head-to-head manner, and lasted for a duration of at least one year. If background blood pressure lowering agents were continued or added during the study, the protocol to do so must have been the same in both study arms.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Nine studies with 11,007 participants were included. Of the included studies, five reported data on total mortality, three reported data on total cardiovascular events, and four reported data on cardiovascular mortality. No study separately reported cardiovascular morbidity. In contrast, eight studies contributed data on WDAE. Included studies were of good to moderate quality. There was no evidence of a difference between ACE inhibitors and ARBs for total mortality (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.88 to 1.10), total cardiovascular events (RR 1.07; 95% CI 0.96 to 1.19), or cardiovascular mortality (RR 0.98; 95% CI 0.85 to 1.13). Conversely, a high level of evidence indicated a slightly lower incidence of WDAE for ARBs as compared with ACE inhibitors (RR 0.83; 95% CI 0.74 to 0.93; absolute risk reduction (ARR) 1.8%, number needed to treat for an additional beneficial outcome (NNTB) 55 over 4.1 years), mainly attributable to a higher incidence of dry cough with ACE inhibitors. The quality of the evidence for mortality and cardiovascular outcomes was limited by possible publication bias, in that several studies were initially eligible for inclusion in this review, but had no extractable data available for the hypertension subgroup. To this end, the evidence for total mortality was judged to be moderate, while the evidence for total cardiovascular events was judged to be low by the GRADE approach.

AUTHORS' CONCLUSIONS

Our analyses found no evidence of a difference in total mortality or cardiovascular outcomes for ARBs as compared with ACE inhibitors, while ARBs caused slightly fewer WDAEs than ACE inhibitors. Although ACE inhibitors have shown efficacy in these outcomes over placebo, our results cannot be used to extrapolate the same conclusion for ARBs directly, which have not been studied in placebo-controlled trials for hypertension. Thus, the substitution of an ARB for an ACE inhibitor, while supported by evidence on grounds of tolerability, must be made in consideration of the weaker evidence for the efficacy of ARBs regarding mortality and morbidity outcomes compared with ACE inhibitors. Additionally, our data mostly derives from participants with existing clinical sequelae of hypertension, and it would be useful to have data from asymptomatic people to increase the generalizability of this review. Unpublished subgroup data of hypertensive participants in existing trials comparing ACE inhibitors and ARBs needs to be made available for this purpose.

The effect of RAAS blockade on the progression of diabetic nephropathy

The renin-angiotensin-aldosterone system (RAAS) has a key role in the regulation of blood pressure, sodium and water balance, and cardiovascular and renal homeostasis. In diabetic nephropathy, excessive activation of the RAAS results in progressive renal damage. RAAS blockade using angiotensin-converting-enzyme inhibitors or angiotensin-receptor blockers is the cornerstone of treatment of diabetic renal disease. Alternative RAAS-blockade strategies include renin inhibition and aldosterone blockade. Data from small initial studies of these agents are promising. However, single-agent interventions do not fully block the RAAS and patients treated with these therapies remain at high residual renal risk. Approaches to optimize drug responses include dietary changes and increasing dosages. The theoretically attractive option of combining different RAAS interventions has also been tested in clinical trials but long-term outcomes were disappointing. However, dual RAAS blockade might represent a good therapeutic option for specific patients. A better knowledge of the pathophysiology of the RAAS is crucial to fully understand the mechanisms of action of RAAS blockers and to exploit their renoprotective effects. Moreover, lifestyle interventions or diagnostic tools might be used to optimize RAAS blockade and identify those patients who are most likely to benefit from the therapy.

Angiotensin-converting enzyme inhibitors versus angiotensin receptor blockers for end-stage renal disease/mortality in type 2 diabetes

AIMS

To compare angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) for end-stage renal disease (ESRD) development and all-cause mortality in veterans with macroalbuminuria and with newly documented type 2 diabetes.

METHODS

A retrospective cohort study utilizing data from the national Department of Veterans Affairs (VA) databases. The study followed 5166 subjects without a history of use of ACEIs or ARBs. To control for differences in baseline characteristics between groups, comparisons of subjects ACEIs and ARBs were made by incorporating propensity scores analysis into multivariate logistic regression. This resulted in adjusted odds ratios and 95% confidence intervals for ESRD development and all-cause mortality.

RESULTS

The sample was followed up to five years with a mean follow-up of three years. Subjects taking ACEIs has lower odds of ESRD development (OR, 0.33 [95% CI, 0.13-0.82]) and all-cause mortality (OR, 0.10 [95% CI, 0.04-0.21]) than ARBs.

CONCLUSIONS

This study shows that ACEIs are associated with lower ESRD development and all-cause mortality than ARBs. This may have implications for guidelines which currently suggest that these two therapeutic classes provide similar benefits in people with newly diagnosed type 2 diabetes and macroalbuminuria.

Therapeutic approaches to slowing the progression of diabetic nephropathy - is less best?

OBJECTIVE

Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors are known to reduce proteinuria and have been the first-line agents in the management of diabetic nephropathy for the past 20 years. This review covers recent studies that compare the benefit of additional blockage of the renin-angiotensin-aldosterone system through combination therapy with an ACE inhibitor and ARB, or a direct renin inhibitor (DRI), to monotherapy.

DESIGN

Primary and review articles that addressed the pathophysiology, diagnosis, and therapeutic options for attenuating the progression of diabetic nephropathy were retrieved through a MEDLINE search (January 1990 to December 2012) and the bibliographies of identified articles were reviewed. English language sources were searched using the following search terms: diabetes mellitus, nephropathy, proteinuria, ACE inhibitors, ARBs, and DRIs.

SETTING

Randomized, placebo-controlled, short- and long-term studies published in peer-reviewed journals that were determined to be methodologically sound, with appropriate statistical analysis of the results, were selected for inclusion in this review.

PARTICIPANTS

Adult (≥18 years) patients with diabetic nephropathy.

MEASUREMENTS

Serum creatinine level was used to estimate glomerular filtration rate (GFR). GFR was calculated using the four-variable Modification of Diet in Renal Disease formula. The urine albumin-to-creatinine ratio was measured at baseline and at the conclusion of each study. A value between 3.4 mg/mmol and below 33.9 mg/mmol was defined as microalbuminuria. A value of 33.9 mg/mmol or more (approximately 300 mg/g creatinine) was defined as macroalbuminuria.

RESULTS

ACE inhibitors and ARBs are now the mainstay of treatment for diabetic nephropathy. However, combination therapy with an ACE inhibitor and an ARB, or DRI, has not been found to be more effective than monotherapy with an ACE inhibitor or ARB, and may increase the risk of hyperkalemia or acute kidney injury.

CONCLUSION

Both ACE inhibitors and ARBs remain the first-line agents in attenuating the progression of diabetic nephropathy; however, recent studies suggest that combining an ACE inhibitor with an ARB, or combining a DRI with an ACE inhibitor or ARB, may increase adverse events without clinical benefits to offset them.

Updated report on comparative effectiveness of ACE inhibitors, ARBs, and direct renin inhibitors for patients with essential hypertension: much more data, little new information

OBJECTIVES

A 2007 systematic review compared angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) in patients with hypertension. Direct renin inhibitors (DRIs) have since been introduced, and significant new research has been published. We sought to update and expand the 2007 review.

DATA SOURCES

We searched MEDLINE and EMBASE (through December 2010) and selected other sources for relevant English-language trials.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

We included studies that directly compared ACE inhibitors, ARBs, and/or DRIs in at least 20 total adults with essential hypertension; had at least 12 weeks of follow-up; and reported at least one outcome of interest. Ninety-seven (97) studies (36 new since 2007) directly comparing ACE inhibitors versus ARBs and three studies directly comparing DRIs to ACE inhibitor inhibitors or ARBs were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

A standard protocol was used to extract data on study design, interventions, population characteristics, and outcomes; evaluate study quality; and summarize the evidence.

RESULTS

In spite of substantial new evidence, none of the conclusions from the 2007 review changed. The level of evidence remains high for equivalence between ACE inhibitors and ARBs for blood pressure lowering and use as single antihypertensive agents, as well as for superiority of ARBs for short-term adverse events (primarily cough). However, the new evidence was insufficient on long-term cardiovascular outcomes, quality of life, progression of renal disease, medication adherence or persistence, rates of angioedema, and differences in key patient subgroups.

LIMITATIONS

Included studies were limited by follow-up duration, protocol heterogeneity, and infrequent reporting on patient subgroups.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Evidence does not support a meaningful difference between ACE inhibitors and ARBs for any outcome except medication side effects. Few, if any, of the questions that were not answered in the 2007 report have been addressed by the 36 new studies. Future research in this area should consider areas of uncertainty and be prioritized accordingly.

Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and combined therapy in patients with micro- and macroalbuminuria and other cardiovascular risk factors: a systematic review of randomized controlled trials

BACKGROUND

A recent clinical trial showed harmful renal effects with the combined use of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-II receptor blockers (ARB) in people with diabetes or vascular disease. We examined the benefits and risks of these agents in people with albuminuria and one or more cardiovascular risk factors.

METHODS

MEDLINE, EMBASE and Renal Health Library were searched for trials comparing ACEI, ARB or their combination with placebo or with one another in people with albuminuria and one or more cardiovascular risk factor.

RESULTS

Eighty-five trials (21,708 patients) were included. There was no significant reduction in the risk of all-cause mortality or fatal cardiac-cerebrovascular outcomes with ACEI versus placebo, ARB versus placebo, ACEI versus ARB or with combined therapy with ACEI + ARB versus monotherapy. There was a significant reduction in the risk of nonfatal cardiovascular events with ACEI versus placebo but not with ARB versus placebo, ACEI versus ARB or with combined therapy with ACEI + ARB versus monotherapy. Development of end-stage kidney disease and progression of microalbuminuria to macroalbuminuria were reduced significantly with ACEI versus placebo and ARB versus placebo but not with combined therapy with ACEI + ARB versus monotherapy.

CONCLUSIONS

ACEI and ARB exert independent renal and nonfatal cardiovascular benefits while their effects on mortality and fatal cardiovascular disease are uncertain. There is a lack of evidence to support the use of combination therapy. A comparative clinical trial with ACE, ARB and its combination in people with albuminuria and a cardiovascular risk factor is warranted.

Evidence-based approach for managing hypertension in type 2 diabetes

Blood pressure (BP) control is a critical part of managing patients with type 2 diabetes. Perhaps it is the single most important aspect of diabetes care, which unlike hyperglycemia and dyslipidemia can reduce both micro- and macrovascular complications. Hypertension is more prevalent in individuals with diabetes than general population, and in most cases its treatment requires two or more pharmacological agents (about 30% of individuals with diabetes need 3 or more medications to control BP). In this article we describe the key evidence that has contributed to our understanding that reduced BP translates into positive micro- and macrovascular outcomes. We review the data supporting current recommendation for BP target < 130/80 mmHg. Two studies suggest that a lower BP goal could be even more beneficial. We also present the comparative benefits of various antihypertensive drugs in reducing diabetes-related micro- and macrovascular complications. Finally we propose an evidence-based algorithm of how to initiate and titrate antihypertensive pharmacotherapy in affected individuals. Overall, achieving BP < 130/80 mmHg is more important than searching for the “best” antihypertensive agent in patients with diabetes.

The role of renin angiotensin system inhibition in kidney repair

Chronic kidney diseases share common pathogenic mechanisms that, independently from the initial injury, lead to glomerular hyperfiltration, proteinuria, and progressive renal scarring and function loss. Inhibition of the renin angiotensin system (RAS) has been consistently found to reduce or halt the progressive deterioration of renal function through reduction of blood pressure and proteinuria, the two main determinants of renal function decline. In few instances, RAS inhibition may even promote amelioration of the glomerular filtration rate. Animal data suggest that chronic therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor type I blockers promotes regression of glomerulosclerosis, even in later phases of the disease. In humans, studies investigating the effect of angiotensin II inhibition on renal structural changes have shown inconsistent results, possibly due to small numbers and/or short duration of follow-up. Whether regression of glomerulosclerosis relies on a direct regenerative effect of RAS inhibition or on spontaneous kidney self-repair after the injury has been removed is still unknown. Improved understanding of mechanisms that promote renal regeneration may help in designing specific therapies to prevent the development of end-stage renal disease. This is a desirable goal, considering the economic burden of chronic kidney diseases and their effect on morbidity and mortality.

Telmisartan: a different angiotensin II receptor blocker protecting a different population?

The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET()) showed that the angiotensin II receptor blocker (ARB) telmisartan was as protective as the reference-standard ramipril in a broad cross-section of patients at increased cardiovascular risk, but was better tolerated. Telmisartan has a unique profile among ARBs, with a high affinity for the angiotensin II type 1 receptor, a long duration of receptor binding, a high lipophilicity and a long plasma half life. This leads to sustained and powerful blood pressure lowering when compared with the first marketed ARBs, such as losartan and valsartan. Some pharmacological properties of telmisartan clearly distinguish it from other members of the ARB class and may contribute to the clinical effects seen with telmisartan. A class effect for ARBs cannot be assumed. To date, telmisartan is the only ARB that has been shown to reduce cardiovascular risk in at-risk cardiovascular patients.

New standards in hypertension and cardiovascular risk management: focus on telmisartan

Blockade of the renin–angiotensin system is an important approach in managing high blood pressure, and has increasingly been shown to affect cardiovascular disease processes mediated by angiotensin II throughout the cardiovascular and renal continua. Telmisartan is an angiotensin II receptor blocker (ARB) displaying unique pharmacologic properties, including a longer half life than any other ARB, that result in large and sustained reductions of blood pressure. In patients with mild-to-moderate hypertension, telmisartan has proved superior to other antihypertensive agents (valsartan, losartan, ramipril, perindopril, and atenolol) in controlling blood pressure particularly towards the end of the dosing interval. There is also clinical evidence that telmisartan reduces left ventricular hypertrophy, reduces arterial stiffness and the recurrence of atrial fibrillation, and confers renoprotection. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET^®) study has demonstrated that telmisartan has similar cardiovascular protective effects to ramipril in a large, high-risk patient population but was better tolerated. The powerful and sustained blood pressure control apparent in clinical trials, together with cardiovascular protection and tolerability demonstrated in ONTARGET^® means that telmisartan may be a preferred option for patients with hypertension.

Effects of renin-angiotensin system blockers on renal outcomes and all-cause mortality in patients with diabetic nephropathy: an updated meta-analysis

BACKGROUND

In contrast to previous studies, recent data questioned the ability of renin-angiotensin-aldosterone system (RAAS) blockers to delay progression of diabetic nephropathy. This study evaluated the effect of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-receptor blockers (ARBs) in patients with diabetic nephropathy.

METHODS

A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed to identify randomized trials published up to June 2007 comparing the effects of ACEIs or ARBs with placebo and/or a regimen not including a RAAS blocker on the incidence of end-stage renal disease (ESRD), doubling of serum creatinine (DSC), or death from any cause in patients with diabetic nephropathy. Treatment effects were summarized as relative risks (RRs) using the Mantel-Haenszel fixed-effects model.

RESULTS

Of the 1,028 originally identified studies, 24 fulfilled the inclusion criteria (20 using ACEIs and 4 using ARBs). Use of ACEIs was associated with a trend toward reduction of ESRD incidence (RR 0.70; 95% confidence interval (CI) 0.46-1.05) and use of ARBs with significant reduction of ESRD risk (RR 0.78; 95% CI 0.67-0.91). Both drug classes were associated with reduction in the risk of DSC (RR 0.71; 95% CI 0.56-0.91 for ACEIs and RR 0.79; 95% CI 0.68-0.91 for ARBs) but none affected all-cause mortality (RR 0.96; 95% CI 0.85-1.09 for ACEIs and RR 0.99; 95% CI 0.85-1.16 for ARBs).

CONCLUSION

Treatment of patients with diabetic nephropathy with a RAAS blocker reduces the risks of ESRD and DSC, but does not affect all-cause mortality. These findings are added to the evidence of a renoprotective role of RAAS blockers in such patients.

Approaches to testing new treatments in autosomal dominant polycystic kidney disease: insights from the CRISP and HALT-PKD studies

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited systemic disease characterized by a prolonged subclinical course of gradual renal cyst expansion, resulting in massively enlarged kidneys and renal failure by the fifth to sixth decade. Renal cyst expansion results in intrarenal ischemia and activation of the renin-angiotensin-aldosterone system (RAAS) and relates to the development and maintenance of hypertension in ADPKD. Hypertension relates to disease progression in ADPKD with regard to renal volume, proteinuria, cardiovascular complications, and progression to end-stage renal disease. Novel magnetic resonance imaging methods developed in the Consortium for Radiologic Imaging for the Study of Polycystic Kidney Disease (CRISP) provide accurate estimates of change in renal volume over a short period of time in ADPKD patients with intact renal function. In CRISP an increase in renal volume of 63.4 ml/yr was found. PKD1 status, male gender, hypertension, reduced renal blood flow, and proteinuria are associated with increased renal volume and change in renal volume over time. HALT-Polycystic Kidney Disease (HALT-PKD) is designed to test whether blockade of RAAS and/or rigorous blood pressure control play a role in slowing renal progression during early (using magnetic resonance imaging methods developed in CRISP) and during late (using measures, including composite of time to doubling of serum creatinine, onset of end-stage renal disease, or death) phases in ADPKD. Findings from CRISP and the rationale for interventions in ADPKD are described, and the design of the HALT-PKD clinical trial is outlined.

A cost-effectiveness analysis of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in diabetic nephropathy

The aim of this study was to estimate the cost-effectiveness of renin-angiotensin-aldosterone system blockers in patients with diabetic nephropathy. A cost-effectiveness analysis was performed based on a meta-analysis of studies investigating the effect of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) as part of a treatment regimen on the incidence of end-stage renal disease (ESRD) in patients with diabetic nephropathy. The primary outcome was the cost to prevent 1 patient from developing ESRD. Cost analysis was performed from a third-party payer perspective in 2006 US dollars. As part of a treatment regimen, ARBs significantly reduced the incidence of ESRD and doubling of serum creatinine concentration (P<.05) but not total mortality. The cost to prevent 1 patient from developing ESRD was $31,729 (95% confidence interval, $19,443-$85,442; P<.01), $189,190 (P=.13) and $51,585 (P=.068) for patients receiving ARBs, ACE inhibitors, or either of them, respectively. This study demonstrates that blocking the RAAS, which delays the progression to ESRD, appears to be cost-effective. The current analysis favors ARBs in terms of cost-effectiveness.

Continued smoking exacerbates but cessation ameliorates progression of early type 2 diabetic nephropathy

PURPOSE

We tested the hypothesis that continued cigarette smoking exacerbates and its cessation ameliorates progression of the early nephropathy of type 2 diabetes mellitus (DM2) from microalbuminuria to macroalbuminuria.

METHODS

We recruited 91 DM2 subjects with microalbuminuria, 39 nonsmokers and 52 smokers. Smokers underwent smoking cessation intervention with 11 of the 52 smokers quitting, yielding 3 groups: nonsmokers (NS, n = 39), continued smokers (S, n = 41), and quitting smokers (Quit, n = 11), all on angiotensin converting enzyme inhibition (ACEI), treated toward recommended BP and glycemic targets, and followed prospectively for 5 years. Subjects had yearly measurements of estimated glomerular filtration rate (eGFR) and albumin (mg)-to-creatinine (g) ratios (alb/cr) in spot morning urines. Comparison of changes in characteristics was done using analysis of variance, with all pair wise multiple comparison procedure at alpha = 0.05.

RESULTS

Although average urine alb/cr was not different among groups at recruitment, 7 of the 41 S (17%) but none of the 50 NS or Quit progressed to macroalbuminuria (P < 0.003). eGFR decline rate was faster in S (-1.79 +/- 0.35 mL/min/yr) than in NS or Quit (-1.30 +/- 0.43 and -1.54 +/- 0.37 mL/min/yr, respectively, P < 0.001). Multivariate analysis revealed smoking to be the only measured baseline factor that influenced eGFR decline rate (P < 0.041).

CONCLUSION

Smoking exacerbates progression of early to advanced DM2 nephropathy and its cessation is an effective kidney-protective intervention in the early nephropathy of DM2.

Microalbuminuria screening in patients with hypertension: recommendations for clinical practice

INTRODUCTION

Correlations between renal and cardiovascular (CV) pathologies in advanced kidney or heart disease are well characterised, but less clearly defined in the early stages. Microalbuminuria, in addition to being an early sign of kidney damage, is often found in patients with essential hypertension, suggesting that it may reflect early vascular abnormalities.

EVIDENCE FROM LITERATURE

Studies have shown that even very low levels of microalbuminuria strongly correlate with CV risk: albumin excretion rates as low as 4.8 microg/min, well below the microalbuminuria thresholds stated in current clinical guidelines, are associated with increased risk of CV and cerebrovascular disease, independent of the presence of other risk factors. Increased microalbuminuria indicates endothelial dysfunction or developing atherosclerosis and predicts end-organ damage, major cardio or cerebrovascular events and death.

CLINICAL ASPECTS

Available tests for screening microalbuminuria are sensitive, reliable and accessible; current European and US guidelines advocate annual screening in patients with diabetes and wherever possible in non-diabetic patients with hypertension. Early identification of high-risk patients through detection of microalbuminuria allows selection of aggressive treatment to slow disease progression.

THERAPEUTIC IMPLICATIONS

Antihypertensive agents providing angiotensin II blockade are recommended for the treatment of hypertensive patients with microalbuminuria, regardless of diabetes and/or early or overt nephropathy. Treatment with angiotensin II receptor blockers provides effective reduction of microalbuminuria and blood pressure, and long-term prevention of CV events beyond blood pressure reduction. In addition, pharmacoeconomic studies have shown that these long-term benefits translate into a substantially reduced burden on healthcare resources.

Angiotensin receptor antagonist vs. angiotensin-converting enzyme inhibitor in Asian subjects with type 2 diabetes and albuminuria - a randomized crossover study

BACKGROUND

Subjects with type 2 diabetes mellitus (T2DM) and albuminuria are at risk for progressive diabetic nephropathy. The relative blood pressure lowering and antialbuminuric efficacy of angiotensin receptor antagonist (ARB) vs. angiotensin-converting enzyme (ACE) inhibitor has not been well studied.

METHODS

Forty-one ARB- and ACE inhibitor-naive T2DM subjects with albuminuria (>30 mg/g creatinine) were given either 50 mg of losartan (ARB) or 20 mg of quinapril (ACE inhibitor) (50% maximum dose) for 4 weeks, with a 4-week wash-out period in-between interventions in a crossover fashion. The order of intervention was randomized. The primary endpoint was the reduction of blood pressure and albuminuria. Secondary endpoint was changes in plasma transforming growth factor beta (TGF-beta).

RESULTS

Among the 41 subjects, 66% were male. The mean age (s.d.) was 52 (10) years, and duration of diabetes was 8 (14) years. Blood pressure reduction (though not statistically significant) was similar on both interventions [systolic: losartan 3 (15) vs. quinapril 2 (13) mmHg, p = 0.52; diastolic: losartan 1 (9) vs. quinapril 2 (8) mmHg, p = 0.55]. However, amelioration of albuminuria [mean (s.e.)] was significantly greater with losartan [losartan vs. quinapril: -93 (82) vs. -49 (65) mg/g, p = 0.02]. There was no change in plasma TGF-beta levels [mean (s.d.)] on either treatment, losartan [before 12.1 (8.9) vs. after 11.9 (9.6) ng/ml, p = 0.68] and quinapril [11.1 (7.9) vs. 11.1 (7.8) ng/ml, p = 0.87).

CONCLUSION

In Asian subjects with T2DM and albuminuria, 4 weeks of losartan therapy at 50 mg daily appeared to have greater antialbuminuric effect than 20 mg of quinapril.

Nefropatia diabética e doença cardíaca

Pacientes em diferentes estágios de nefropatia diabética (ND) apresentam freqüentemente comprometimento cardíaco expresso por isquemia miocárdica e/ou cardiomiopatia diabética. Estas alterações já estão presentes em estágios iniciais da ND e provavelmente mesmo antes de a excreção urinária de albumina (EUA) atingir níveis tradicionalmente diagnósticos de microalbuminúria. As alterações cardíacas são responsáveis por uma proporção significativa de mortes nos pacientes com ND e podem ser reduzidas através de intervenção nos múltiplos fatores de risco cardiovascular encontrados nesses pacientes. A avaliação de doença cardíaca deve idealmente ser realizada em todos os pacientes com qualquer grau de ND através de métodos específicos para detectar isquemia e disfunção miocárdica, além do emprego rotineiro da monitorização ambulatorial da pressão arterial em 24 h. Em pacientes com aterosclerose avançada também devem ser avaliadas outras artérias (carótidas, aorta, renais). O tratamento rigoroso da hipertensão arterial, o uso de fármacos cardioprotetores, o tratamento da dislipidemia e da anemia, assim como o emprego de medicamentos anti-plaquetários, poderão reduzir a elevada mortalidade cardiovascular na ND.

Blood pressure lowering for the prevention and treatment of diabetic kidney disease

The current pandemic of diabetes mellitus will inevitably be followed by an epidemic of chronic kidney disease. It is anticipated that 25-40% of patients with type 1 diabetes and 5-40% of patients with type 2 diabetes will ultimately develop diabetic kidney disease. The control of blood pressure represents a key component for the prevention and management of diabetic nephropathy. There is a strong epidemiological connection between hypertension in diabetes and adverse outcomes in diabetes. Hypertension is closely linked to insulin resistance as part of the 'metabolic syndrome'. Diabetic nephropathy may lead to hypertension through direct actions on renal sodium handling, vascular compliance and vasomotor function. Recent clinical trials also support the utility of blood pressure reduction in the prevention of diabetic kidney disease. In patients with normoalbuminuria, transition to microalbuminuria can be prevented by blood pressure reduction. This action appears to be significant regardless of whether patients have elevated blood pressure or not. The efficacy of ACE inhibition appears to be greater than that achieved by other agents with a similar degree of blood pressure reduction; although large observational studies suggest the risk of microalbuminuria may be reduced by blood pressure reduction, regardless of modality. In patients with established microalbuminuria, ACE inhibitors and angiotensin receptor antagonists (angiotensin receptor blockers [ARBs]) consistently reduce the risk of progression from microalbuminuria to macroalbuminuria, over and above their antihypertensive actions. The clinical utility of combining these strategies remains to be established. In patients with overt nephropathy, blood pressure reduction is associated with reduced urinary albumin excretion and, subsequently, a reduced risk of renal impairment or end stage renal disease. In addition to actions on systemic blood pressure, it is now clear that ACE inhibitors and ARBs also reduce proteinuria in patients with diabetes. This anti-proteinuric activity is distinct from other antihypertensive agents and diuretics. Although there is a clear physiological rationale for blockade of the renin angiotensin system, which is strongly supported by clinical studies, to achieve the optimal lowering of blood pressure, particularly in the setting of established diabetic renal disease, a number of different antihypertensive agents will always be needed. In the end, the choice of agents should be individualised to achieve the maximal tolerated reduction in blood pressure and albuminuria. Ultimately, no matter how it is achieved, so long as it is achieved, renal risk can be reduced by agents that lower blood pressure and albuminuria.